PHYSICS DIVISION SEMIANNUAL PROGRESS REPORT FOR PERIOD ENDING MARCH 10, 1958

Technical Report · Tue Jun 10 00:00:00 EDT 1958

DOI:https://doi.org/10.2172/4342001· OSTI ID:4342001

A new formalism is described which allows the consistent introduction into relativistic quantum theory of a cut-off momentum without use of an arbitary form factor. Information on the gamma decay characteristics is obtained for the second 2/sup +/ states of W, Os, and Pt nuclei. The total neutron cross sections for C/sup 12/, C/sup 13/, and Ne/sup 21/ were measured. The S/sup 32/(n, alpha )Si/sup 29/ cross section was measured relative to the fission cross section of U/ sup 238/ as a function of incident neutron energy in the range 1.3 < E/sub n/, < 3.8 Mev. Total neutron cross sections were measured for several separated isotopes in the kev energy range with an energy resolution of 3%. The results on Cu/sup 65/ and Fe/sup 57/ are given. Total and scattering neutron cross sections of several elements were measured with the new high-intensity time-of-flight spectrometer. Parameters of resonances up to 300 ev are given for iodine and gold. The spin states of several resonances in W/sup 183/ and silver were determined from scattering and total cross section measurements. Cross sections for (p,n) reactions in cadmium and tellurium isotopes were measured from about 2.5 to 5.5 Mev. Over most of the energy range the cross sections of the isotopes of one element are in constant ratio and increase with mass number. The Cd/sup 112/ threshold was found to be 3.44 plus or minus 0.02 Mev. Absolute cross sections were measured for several (p,n) and ( alpha ,n) reactions of light nuclei. A neutron diffraction investigation of MnI/sub 2/ was made. The results indicate that Mnl/sub 2/ is antiferromagnetic, with a Neel temperature of 3.4 deg K. Neutron diffraction investigations were carried out on MnCl/sub 2/, metallic cerium, metallic neodymiuma, CoCl/sub 2/, and FeCl/sub 2/ to determine their magnetic properties. The antiferromagnctic structure of MnF/sub 3/ was determined and was found to be similar to that in LaMnO/sub 3/. The magnetic coupling properties are briefly discussed. The energy levels of the configuration 6p/sup 2/ in HgI were investigated. The infrared spectra of PH/sub 2/D, PHD/sub 2/, and PD/sub 3/ was recorded by the multiple-cell compensation technique. A compilation was made of available data on the spectra of Th(IV), Th(III), Th(II), and Th(I), including energy levels and classified lines with Zeemnan effects and isotope shifts, as well as certain data on unclassified lines. The present status of knowledge of these spectra is discussed. The role of spectroscopy in thermonuclear research is reviewed briefly. A spherical electrostatic spin rotator is being used to study the polarization of electrons in beta decay. A germanium p-n surface barrier counter was developed which is suitable for alpha particle and fission-fragment counting between 1 and 77 deg K. The Duo-Plasmatron, a new ion source developed in Germany, is dscussed. (For preceding period see ORNL-2204.) (W.D.M.)

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-12-010684
• OSTI ID: 4342001
• Report Number(s): ORNL-2501
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-58
• Country of Publication: United States
• Language: English

Related Subjects

PHYSICS
ALPHA PARTICLES- BARRIERS- COUNTERS- ELECTRIC CONDUCTIVITY- FISSION PRODUCTS- GERMANIUM- LOW TEMPERATURE
ALPHA PARTICLES- CROSS SECTIONS- ENERGY- ENERGY RANGE- FISSION- MEASURED VALUES- SILICON 29- SULFUR 32- URANIUM 238
ALPHA PARTICLES- CROSS SECTIONS- MASS- MEASURED VALUES- NEUTRONS- NUCLEAR REACTIONS- NUCLEI- PROTONS
ANTIFERROMAGNETISM- CERIUM- COBALT CHLORIDES- DIFFRACTION- ENERGY LEVELS- INTERMETALLIC COMPOUNDS- IRON CHLORIDES- LANTHANUM COMPOUNDS- LOW TEMPERATURE- MAGNETISM- MANGANESE CHLORIDES- MANGANESE COMPOUNDS- MANGANESE IODIDES- MANGANESE OXIDES- MEASURED VALUES- MERCURY IODIDES- METALS- NE